Background: A nation-wide cross sectional study was conducted in Brazil in order to estimate the HIV prevalence and sexual behavior among MSM. In this abstract we investigate violence frequency, and help seeking decisionsMethods: 3,858 MSM were recruited by the RDS method in ten Brazilian cities. Basic descriptive analyses with no adjustments are shown.Results: Preliminary results revealed that 59% defined themselves as “gays”/homosexuals/MSM, 29% as bisexuals, and 7.5% as heterosexuals. 8.3% were HIV+ before the study. Life-time discrimination because of their sexual orientation was referred by 44%, and in the previous year by 31% (74% occurred more than once). Life-time gay-related physical aggressions were reported by 14%, and 8% had suffered physical aggression in the last year The aggressor of the physical homophobic violence was the stable sexual partner in 8.2%, casual partner in 7.3%, male commercial sex worker in 4.8%, relative/work mate in 26.7%, friend/acquaintance (29.6%), police officer (8.9%), unknown person (37.8%). Life-time sexual abuse were reported by 15%, and the median age was 15 years. The perpetrator of sexual abuse was the stable sexual partner in 7.4%, casual partner in 12.4%, male commercial sex worker in 3%, relative/work mate (28.1%), friend/acquaintance (31.0%), police officer (2.8%), unknown person (20.7%). Medical assistance was sought by 9.9% of violence victims and 9.1% reported to police authorities. Among those who referred being target of physical violence, a significant proportion were HIV+ (29.3% vs 15.3%; X2=20,9, p< 0.0001) and of low economic status (16% vs11.9%; X2=20.9, p< 0.0001). Among those who referred sexual abuse, a higher proportion were classified as low economic status (16.7% vs 13.8 ; X2=4.7, p< 0.02).Conclusions: Unrevealed non lethal violence towards MSM can be detected by surveys. Preliminary results point out for multiple determinants that indicate the need of intersectorial interventions for the prevention of violence in this specific group.